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COLORADO PARKS & WILDLIFE River Otter ASSESSING QUALITY FOR PRIORITY WILDLIFE IN COLORADO WETLANDS

Species Distribution Range Northern river otters historically ranged throughout most of the United States and Canada but were extirpated from much of their range in the west. Reintroductions of otter to Colorado began in 1976, and they are now found in small numbers throughout most of western Colorado with a more scattered distribution in eastern Colorado. © TOM KOERNER, USFWS KOERNER, TOM © Northern river otters ( canadensis, Family ) occupy streams and ponds across Colorado’s western slope. Species Description Conservation Status Identification Northern river otters are listed as Northern river otters vary in length least concern by the International from 26–42 inches, with males larger Colorado map based on Boyle (2006), NDIS (2014), and Union for the Conservation of Nature. institutional knowledge of Colorado Parks and Wildlife than females. Males weigh on average In Colorado, they are listed as a biologists. 25 pounds; females weigh about 18 threatened, Tier 2, Species of Greatest pounds. Their long tapered tails make Conservation Need (CPW 2015). up about one third their length.

Preferred River otters may inhabit nearly every aquatic habitat; however, they are most likely to occupy beaver ponds, stream channels, and warm sloughs.

Diet Otters favor but also consume , mollusks, frogs, snakes, turtles, salamanders, birds, , and fruit. © U.S. FISH AND WILDLIFE SERVICE WILDLIFE AND FISH U.S. ©

Version Date: November 2020

COLORADO PARKS & WILDLIFE • 6060 Broadway, Denver, CO 80216 • (303) 297-1192 • cpw.state.co.us Preferred Habitat Conditions Beaver often associated with beaver activity or old beaver structures Dominant vegetation healthy riparian vegetation Habitat size longer reaches usually better Shore complexity undercut banks and other complex features Structures and debris habitat complexity, including woody debris and log jams Stream order >4th order Management Recommendations This fact sheet contains easy-to-use guidelines for understanding habitat needs of Colorado Parks and Wildlife priority wetland-dependent wildlife. Biologists with

expertise in river otters have suggested numerous practical steps that can be taken to THOMAS KEN © improve habitat quality for this species. Acknowledgements Eric Odell and Scott Wait (Colorado Parks Hydrology and Wildlife) reviewed an earlier version and • Maintain natural regime to extent possible. provided input on preferred habitat conditions. • Protect instream and seasonal flow regimes. Suggested Reading and Citations • Enhance and/or protect stream and habitat connectivity. Boyle, S. 2006. North American river otter (Lontra canadensis): a technical conservation assessment. USDA Forest Service, Rocky Vegetation Mountain Region. • Maintain or recreate conditions favoring healthy riparian vegetation. CPW (Colorado Parks and Wildlife). 2015. State Wildlife Action Plan: A Strategy for • Encourage new recruitment of trees. Conserving Wildlife in Colorado. Denver, • Manage for age diversity. Colorado. Crowley, S., C. J. Johnson, and D. Hodder. 2012. Land Use / Other Spatial and behavioral scales of habitat selection and activity by river otters at latrine • Enhance and/or protect bank structure. sites. Journal of Mammalogy 93: 170-182. • Enhance and/or protect flood plain. Dubuc, L. J., W. B. Krohn, and R. B. Owen, Jr. 1990. Predicting occurrence of river otters • Enhance and/or protect good water quality. by habitat on Mount Desert Island, Maine. • Protect potential upland denning sites from flooding. Journal of Wildlife Management 54: 594-599. • Manage for prey base (e.g., fish). Gorman, T. A., J. D. Erb, B. R. McMillan, and D. J. Martin. 2006. Space use and sociality of river otters (Lontra canadensis) in Minnesota. Conservation Journal of Mammalogy 87: 740-747. • Monitor and control commercial harvest to maintain desirable population Melquist, W. E., and M. G. Hornocker. 1983. numbers. Ecology of river otters in west central Idaho. Wildlife Monographs 83: 3-60. • Form and maintain partnerships across jurisdictional boundaries to protect connectivity and long stream reaches. © TOM KOERNER, USFWS KOERNER, TOM © © BRIAN TANG, WW.HARDRAIN.ME TANG, BRIAN © © MIKE NORDELL, USFWS NORDELL, MIKE ©

COLORADO PARKS & WILDLIFE • 6060 Broadway, Denver, CO 80216 • (303) 297-1192 • cpw.state.co.us Habitat Scorecard for River Otters (v. Nov 2020) Assessment of habitat before and after restoration or management actions

Project Name: ______Project Area (acres): ______Habitat Area (acres): ______Size of Contiguous Habitat outside Project Area (acres): ______Ownership (circle): Same / Different / Conservation Easement Scorecard Instructions: Enter one value that best describes early to mid-summer conditions of each habitat variable, using the numbers in the value column. Habitat variables are in shaded boxes; ranges of condition are directly below each variable. If condition is outside range or is not described, enter a zero. Project Area and Habitat Area: The project area includes the entire area affected by the project. The habitat is the area that will provide (in case of pre-project) or does provide (post-project) habitat for each potential target species within the project area. The habitat area may be the same size as the project area or it might be smaller and it may be defined differently for different target species. If there is contiguous habitat area outside the project area, note the size and whether the ownership of the contiguous areas is the same or different and whether it is under conservation easement or other habitat protection. If the habitat area within your project area is noncontiguous and/or if sections are in very different conditions, consider using multiple scorecards so that each scorecard represents the general conditions. If you use multiple scorecards, identify each habitat area on a map.

Expected Actual Key habitat variable and conditions Value Pre- Post- Post- Project Project Project

Date of assessment

Woody objects, e.g., logs, log jams >5 large logs 17.8 1 – 4 large logs 11.9 Beaver activity (current or remains) Current activity or recent remnants 17.8 Historic remnants 11.9 Percent canopy cover >6.6 feet >50% 17.0 >30 – 50% 11.3 20 – 30% 5.7 Height of canopy cover >50 feet 17.0 >16 – 50 feet 11.3 8 inches – 16 feet 5.7 Number of complex shore features (e.g., undercut banks) >5 17.0 1 – 4 11.3 Percent of water > 8 inches deep >90% 13.4 >80 – 90% 8.9 40 – 80% 4.5

Total (of 100 possible): add all numbers in before or after columns